Hi Lisa friends,
I've written a floppy disk bootloader for Lisa and released it into the public domain. You can find it here:
For now it only works with 3.5" disks, but adapting it to Twiggy should be fairly straightforward.
A supporting script for creating bootable .dc42 disk images is included.
The bootloader has been tested on simulated and actual Lisa hardware.
The documentation and comments aim to make the bootloader's code and operation understandable to the novice.
Thanks are due to Ray for LisaEm, James for helpful notes in the BLU manual, the archivists at Bitsavers, and various other online resources.
Cheers,
--Tom